Spark-plug.



R. W. SCHULTZ.

SPARK PLUG.

APPLICATION FILED JUNE 24. [916.

Patented May 28,1918.

s E S S F. N n w ATTOR N EY ROBERT W. SCHULTZ, 0F CINCINNATI, OHIO.

OFFICE.

SPARK-PLUG.

Specification of Letters Patent.

Patented'May 28, 1918.

Application filed June e4, 1916. Serial in. 105,648

To all whom it may concern:

Be it known that I, Rosana W. Scnuurz, a citizen of the United States. residing at Cincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Spark-Plugs, of which the following is a specification.

My. invention relates to ignition devices, and more particularly to an improved spark lu p T he invention has more special reference to an ignition device of the character stated whereby a variable spark may be produced, consequently rendering a construction highly efficient for use in gas engines and the like,

and in general, providing a device which will enable the engine to derive a much greater driving power.

More particularly, the present invention has reference to the novel construction of a- Qspark plug, which may be said to comprise a casing carrying a plurality of sparking terminals integrally formed thereupon, a

central electrode having a spherical head, which serves as the remaining sparking ter-. minal, the terminals as carried by the casing,

being arranged at relatively different distances from the spherical head, thus, affording means whereby a spark of varying lengths and power may be had.

Among the advantages accruing from the novel arrangement of the sparking terminals may be noted, that the varying sparks will prevent the misfiring of the engine under oil flooded conditions; that a poor combustive mixture as delivered from the carbureter will be ignited thereby also, that the engine will be afforded a much greater get away power.

The annexed drawings and the following description sets forth in detail, certain structures embodying the invention, such dis closed means constituting, however, but one of the various mechanical forms in which Referring more particularly to the drawings, wherein like reference characters designate like or corresponding arts throughout the several views, a suitab e casing is employed, which I have designated by the numeral 1. The upper portion of this casing is provided with a shoulder 2 having formed therein an annular recess 3, a portion of which is screw threaded as at 4:. The portion of the casing 1 as adjacent the shoulder 2 and indicated by the numeral 5 is of greater thickness than the lower portion thereof and has arranged thereabout screw threads 6, whereby the device may be readily turned into engagement with the cylinder head of the particular engine to which the igniting device is to be applied. Arranged upon the lower marginal edge of the casing 1 and laterally disposed therefrom is a finger 7, which constitutes one of the sparking terminals of my improved device, while arranged adjacent the lower marginal edge of the casing 1 at a point substantially diametrically opposite the electrode 7 and extending toward the latter is a second electrode 8, it being noted that this electrode is of less v length than the first mentioned electrode, the

' quently the electrodes 7 and 8 of the sleeve 1 are bendable toand from the spherical elec trode 17 so that the spark gap therebetween can be adjusted. Obviously the length of the sparks between the electrodes 7 and 8 will be governed by the distance to which the electrodes have been bent toward the spherical electrode 17 and by the impressed electro motive force. The manner of securing an adjustment of the sparks is thus simplified as will be obvious from the above explanation and an inspection of Fig. 1 of the drawing.

An insulating plug, referred to generally by the numeral 9 is positioned within the casing 1" and has formed thereupon a laterally distended flange 10, also, constructed from insulating material. The upper portion of the insulating plug is of a frustoconical formation and recelves upon its up- J 8, carried upon the lower marginal tended flange 10, thus,

to have threaded into engagement therewith, the usual electrical conductor securing nuts 16, while the lower portion of this electrode is provided with a spherical head 17, which head, as is obvious extendsinto proximity to the sparking terminals 7 and edge of the casing.

The flange 10 as formed upon the plug 9 is receivable within the annular recess 3,

arranged in the upper portion of the casing 1, the washer 18; being formed of suitable jacent the side of the spherical head 17,whilethe electrode 7 extends to a point below this spherical head. Accordingly, when the electrode 1% is rotated in either direction, it is obvious that deposits of carbon will be ositively removed from either one or bot of these electrodes, since a deposit of carbon on the head 17 when moved from the electrode 7 on one side will not have a support and then coming into engagement with the electrode 8 will be pushed from the head 17.

Accordingly, the rotation of the electrode will cause deposits of carbon to be displaced to prevent a short circuiting over the electrodes at the end.

Referring now to the operation of the device as hereinbefore described, current is supplied to the electrodes 7 and 8 and to the electrode 1% in the manner as wellknown to the art. Should the engine be running at a low rate of speed,the magneto if such is being used, will of course, supply a comparatively small amount of current and conse quently the necessary ignition spark will be produced between the electrode 8 and the adjacent portion of the spherical head 17 oil the electrode 1%, it being noted, that this particular terminal is arranged in closer relation thereto. Should the speed of the engine be increased, and the combustion mixture thereto, necessarily increased, the power as delivered from the magneto will be increased and a spark will be produced between the electrode 7 and that adjacent portion of the spherical head 17, thus, afiording a larger igniting spark. It will be also noted, that as the spark is being produced between the terminal 7 and the spherical head 17, a second spark of less size will so produced between the electrode 8 and its 7 extending nest nor the said spherical head 17, consequently, afl'ording an ignition means which will positively ignite even in exceedingly poor mixture and will also prevent the interference with the ignition of the spark under oilfiooded conditions.

t should benoted that the longitudinal opening 13 is reduced at its lower portion as at 13, thereby forming an annular shoulder 12. The electrode 1% is also reduced as indicated at 14:, whereby said electrode 1d will rest upon said shoulder. As a consequence the electrode 1% will be supported upon the lug 9 without the aid of secondary securing means, such as the nuts 16, as shown in Fig. 1. As is further noted the electrode may be turned slightly, even though a conductor is secured thereto by the nuts 16, whereby carbonwhich may collect between the electrodes 7 and 8 and the head 17 may be easily displaced.

@ther modes. of applying the principle of my invention may be employed, instead of the one explained, change beingmade as regards the mechanism herein disclosed, provided the means stated by the following claim or the equivalent of said stated means be employed.

I therefore claim as my invention A spark plug comprising a casing, an insulating plug carried upon'said casing, said insulating plug having a longitudinally bore forward formed therethrough, said bore being reduced adjacent the lower end of saidplug, thus forming a shoulder adjacent the lower end of said plug, thus forming a shoulder, an electrode fitting in the reduced portion oi said bore, thus causing the electrode to bear upon said shoulder for limiting its movement" in one direction, a head formed upon the lower end of said electrode, said head bearing against the lower end of said plug, thus limiting adjacent portion of the movement of said electrode, a fixed elec;

trode on said casing extending to a point tit:

adjacent the side of said head, a second" fixed electrode on said casing extending to a point below said head, wire attaching means mounted upon said first mentioned electrode, said, first mentioned electrode being free to rotate, thus causing said head to turn for allowing said fixed electrode tov remove deposits of carbon therefrom, while the formation of the reduced portion of said first mentioned electrode will hold said first mentioned electrode against displacement.

in testimony whereof I ailix my'signature in presence of two'witnesses.

noennr w. schema W itnesses G. J. Conn mm, f}. G. ldmrrnnnx'onnn. 

